Drilling muds have long been used in drilling processes. Universally, a drilling mud is used in a circulating system with a rotary well drilling mechanism. The drilling mud is forced down hole by pumping it down the hollow drill stem through the bit so that it lubricates and cools the bit. Then, the mud is circulated back to the surface and to a settling pit. The drilling mud washes out the cuttings which have been made from the hole, and the cuttings are carried outside the drill stem to the surface where the coarse particles are caused to be removed and the mud again used in a continuous circulating process. To prevent the loss of the mud in porous strata, the mud must be of a character to seal off such strata and the mud, by its hydrostatic pressure, must prevent the escape of gas, that is, prevent the well from blowing out. To provide the proper hydrostatic pressure, the specific gravity of the mud may be increased by adding heavier material than clay. On the other hand, the drilling fluid must have the proper viscosity, that is, be thick enough to carry out the cuttings, but thin enough to be pumped and to allow the coarse particles to settle out in the surface mud pits so that the mud may be reused.
Until recent years, a drilling mud was thought to be useable and practical if it possessed desirable gel strength, viscosity and water loss properties. However, the disposal of drilling muds or fluids has gradually become an area of prime importance. Such has resulted from potential surface pollution. Restrictions on the disposal of drilling fluids are becoming more stringent thereby substantially increasing the cost of disposal of such fluids. The industry is faced with the probability of additional governmental regulations in regard to the disposal of drilling mud or fluids with a resultant increase in cost. Therefore, much effort has been directed in developing drilling muds or fluids which can be disposed of onsite without creating pollution problems such as soil or plant damage. At the same time, the drilling muds or fluids must still possess the desired physical properties as to viscosity, gel strength, and the like.